Microbial complex microbial inoculant for promoting accumulation of organic carbon in cultivated land soil and preparation method of microbial complex microbial inoculant

Abstract

The invention discloses a composite microbial inoculant for promoting accumulation of organic carbon in cultivated land soil and a preparation method of the composite microbial inoculant, and belongs to the technical field of soil improvement, the composite microbial inoculant comprises 10-20 parts by weight of carbon sequestration functional flora and 20-30 parts by weight of soil improvement flora. Aiming at the characteristics of soil in the dry-hot valley region, the invention provides a novel microbial composite inoculant: carbon sequestration functional bacteria can convert carbon dioxide into organic carbon, so that the content of the organic carbon in the soil is remarkably increased, and the fertility and the structural stability of the soil are further enhanced; the soil improvement flora can promote the plants to absorb nutrients, optimize the soil structure, effectively reduce the toxicity of salt to the plants and improve the soil productivity. The invention provides an innovative solution for solving the problem of soil salinization and increasing the organic carbon content, not only promotes the development of ecological agriculture, but also provides powerful support for agricultural sustainability in dry and hot valley areas.

Description

Technical Field

[0001] The present invention relates to the technical field of soil improvement, and in particular to a microbial composite agent for promoting the accumulation of organic carbon in cultivated soil and a preparation method thereof. Background Art

[0002] As global climate change intensifies, ecosystems in dry and hot regions are facing severe challenges. The unique climatic conditions in dry and hot valleys lead to intense soil evaporation and continuous accumulation of salt, making soil salinization increasingly serious. In addition, long-term and continuous farming has greatly reduced the carbon storage in the soil, and the soil carbon pool has gradually been lost, which in turn causes soil compaction and weakened buffering capacity. This series of problems not only significantly reduces soil fertility, but also has a profound adverse impact on agricultural production and food security. Therefore, research and development of efficient soil improvement technologies has become one of the key research directions in today's agricultural field.

[0003] Although traditional microbial agents are widely used in soil improvement, there are many deficiencies in their actual application in dry and hot valley areas. First, traditional agents are mainly designed for general soil problems, and their effects are significantly limited when faced with extreme temperatures and severe salinization environments. These agents are difficult to maintain activity under drought and high-salt conditions, and the survival rate of microorganisms is low, resulting in short-lived improvement effects. In addition, traditional agents mostly rely on a single or a few microorganisms and lack a systematic functional combination, making it difficult to achieve multi-level soil improvement, especially in terms of organic carbon sequestration. Based on this, there is an urgent need to provide a new type of microbial composite agent that targets the soil characteristics of dry and hot valley areas to overcome the limitations of traditional agents. Summary of the invention

[0004] The purpose of the present invention is to provide a microbial composite agent for promoting the accumulation of organic carbon in cultivated soil and a preparation method thereof, so as to solve the problems existing in the above-mentioned prior art. The microbial composite agent of the present invention has greatly improved its application effect in dry and hot river valley areas through scientific proportioning and multifunctional collaboration, and provides an innovative solution for solving soil salinization and increasing the organic carbon content. It not only promotes the development of ecological agriculture, but also provides strong support for the agricultural sustainability in dry and hot river valley areas.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] The present invention provides a microbial composite agent for promoting the accumulation of organic carbon in cultivated soil, wherein the microbial composite agent comprises 10-20 parts by weight of carbon fixation functional bacteria and 20-30 parts by weight of soil improvement bacteria;

[0007] The carbon fixation functional bacteria include Corynebacterium stationis and Hyphomicrobium denitrificans; the soil improvement bacteria include Pseudomonasfluorescens, Bacillus megaterium, Bacillusmucilaginosa and Bacillus lateralis;

[0008] Optionally, the stagnant Corynebacterium is stagnant Corynebacterium CGMCC 1.844, and the apoptotic microbacterium is apoptotic microbacterium CGMCC 1.15943;

[0009] The stagnant Corynebacterium and the desmochromatium are mixed in the form of bacterial liquid, and the volume ratio of the stagnant Corynebacterium bacterial liquid to the desmochromatium bacterial liquid is 1:1;

[0010] The OD of the stagnant Corynebacterium solution and the desingle-hyphalomycete solution 600 Both are 0.8-1.0.

[0011] Optionally, the Pseudomonas fluorescens is Pseudomonas fluorescens CICC 20066, and the Bacillus megaterium is Bacillus megaterium CICC 10044;

[0012] The Pseudomonas fluorescens, Bacillus megaceus, Bacillus mucilaginosus and Bacillus laterus are mixed in the form of bacterial liquid, and the volume ratio of the Pseudomonas fluorescens bacterial liquid, the Bacillus megaceus bacterial liquid, the Bacillus mucilaginosus bacterial liquid and the Bacillus laterus bacterial liquid is 4:3:3:2;

[0013] The OD values ​​of the Pseudomonas fluorescens bacterial solution, the Bacillus megaceus bacterial solution, the Bacillus mucilaginosus bacterial solution and the Bacillus laterus bacterial solution were 600 Both are 0.8-1.0.

[0014] The present invention also provides a method for preparing the microbial composite agent, comprising the following steps:

[0015] The stagnant Corynebacterium and the desmochromatin Microbacterium are mixed in proportion to obtain a carbon-fixing functional bacterial community;

[0016] Pseudomonas fluorescens, Bacillus megaceus, Bacillus mucilaginosus and Bacillus laterus are mixed in proportion to obtain soil improving bacteria flora;

[0017] The carbon fixation functional bacteria and the soil improvement bacteria are mixed in proportion to obtain a microbial composite agent.

[0018] Optionally, the method further includes the steps of expanding the microbial composite agent and adding a promoter.

[0019] Optionally, the expansion culture is carried out using brown sugar culture medium;

[0020] The brown sugar culture medium comprises the following components: 20 g / L brown sugar, 2 g / L soybean powder, 1 g / L potassium dihydrogen phosphate, 1 g / L magnesium sulfate and 1 g / L sodium chloride, and the pH value is 5.5-7.5.

[0021] Optionally, the accelerator is composed of the following ingredients in weight percentage: 3% glucose, 2% γ-aminophosphoric acid, 2% sodium alginate and 2% glutamic acid, with a pH of 6-7;

[0022] The amount of the accelerator added is 5-11 wt%.

[0023] The present invention also provides the use of the microbial composite agent in improving soil salinization in dry-hot valleys and promoting organic carbon accumulation.

[0024] The present invention also provides a method for improving soil salinization and promoting organic carbon accumulation in a dry and hot valley, comprising the step of applying the microbial composite agent to the soil in the dry and hot valley.

[0025] Optionally, the application amount of the microbial composite agent is 1-3 L / mu.

[0026] The present invention discloses the following technical effects:

[0027] The present invention proposes a novel microbial composite agent based on the soil characteristics of dry and hot valley areas, aiming to overcome the limitations of traditional microbial agents. The microbial composite agent provided by the present invention has the following advantages.

[0028] 1. Significantly improve soil organic carbon accumulation

[0029] The present invention significantly enhances the accumulation capacity of soil organic carbon by scientifically screening and optimizing the combination of multiple carbon fixation functional strains. The core carbon fixation bacteria in the microbial agent have efficient carbon dioxide conversion capabilities, can quickly fix carbon dioxide in the atmosphere and convert it into stable organic carbon compounds, and increase the organic matter content in the soil. This increase not only improves the physical structure of the soil, making it more loose and breathable, but also improves the soil's water retention capacity and enhances its support for plant roots, thereby significantly improving the productivity of cultivated land and crop yields under drought and barren conditions.

[0030] 2. Effectively improve soil salinization

[0031] The present invention makes the microbial agent have excellent environmental adaptability by carefully selecting soil improvement bacteria that are adapted to drought, high salt and extreme temperature conditions, such as Pseudomonas fluorescens and Bacillus megacephala. These bacteria reduce the salt concentration in the soil through biological metabolism, decompose harmful ions, improve the chemical balance of the soil, and neutralize the salinity and alkalinity by secreting organic acids, thereby significantly improving the production performance of salinized soil and promoting the healthy growth of plants.

[0032] 3. Long-lasting microbial activity

[0033] The present invention specially designs a composite promoter, which contains glucose, γ-aminophosphoric acid, glutamic acid and sodium alginate, to provide balanced carbon, nitrogen, phosphorus and other nutrients for microorganisms, and to adjust the pH value and water retention of the soil, creating an ecological environment that is conducive to the long-term activity of microorganisms. This design enables the microbial flora to colonize and reproduce quickly after application, maintain its efficient metabolic activity in the soil, and ensure the durability of the soil improvement effect. Compared with traditional microbial agents, the solution provided by the present invention can significantly extend the active period of the microbial agent in the soil, reduce the frequency of repeated application, thereby reducing agricultural production costs and improving economic benefits.

[0034] 4. Promote sustainable agricultural development and environmental protection

[0035] The microbial composite agent of the present invention is not only effective in improving soil, but also provides innovative support for the sustainable ecological development of dry and hot valley areas. By significantly increasing the organic carbon content of the soil and solidifying more carbon elements, greenhouse gas emissions are reduced, contributing to the mitigation of global warming. At the same time, the use of microbial agents reduces dependence on chemical fertilizers and reduces the pollution of soil and groundwater by chemical substances. Overall, the technology of the present invention provides a win-win solution for achieving green agriculture and environmental protection, and helps to achieve an efficient and eco-friendly agricultural production model in a saline-alkali environment.

[0036] In summary, the microbial composite agent of the present invention has greatly improved its application effect in dry and hot valley areas through scientific proportioning and multifunctional collaboration, and provided an innovative solution for solving soil salinization and increasing organic carbon content. It not only promotes the development of ecological agriculture, but also provides strong support for agricultural sustainability in dry and hot valley areas. DETAILED DESCRIPTION

[0037] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but should be understood as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0038] It should be understood that the terms described in the present invention are only for describing a particular embodiment and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper and lower limits of the scope is also specifically disclosed. The intermediate value in any stated value or stated range, and each smaller range between any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0039] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art. Although the present invention describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0040] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention description without departing from the scope or spirit of the present invention. Other embodiments derived from the present invention description will be apparent to those skilled in the art. The present invention description and examples are exemplary only.

[0041] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0042] The carbon fixation functional bacteria used in the present invention include Corynebacterium stationis and Hyphomicrobium denitrificans, both of which are purchased from the China General Microbiological Culture Collection Center. Among them, the Corynebacterium stationis has a collection number of CGMCC1.844 and the Hyphomicrobium denitrificans has a collection number of CGMCC 1.15943.

[0043] The soil improvement bacteria used in the present invention include Pseudomonas fluorescens, Bacillus megaterium, Bacillus lateralis and Bacillus lateralis. Among them, Pseudomonas fluorescens has a deposit number of CICC 20066 and Bacillus megaterium has a deposit number of CICC 10044, both of which are purchased from the China Industrial Microbiological Culture Collection Center; Bacillus mucilaginosa and Bacillus lateralis are purchased from Shandong Yihao Biotechnology Co., Ltd. The public can obtain the corresponding strains from the above platform.

[0044] Each strain of Corynebacterium stagnans, Desomonas spp., Pseudomonas fluorescens, Bacillus megaceus, Bacillus mucilaginosus and Bacillus laterus was cultured separately in a suitable culture medium, the culture medium formula of which was 10 g / L amino acids, 5 g / L vitamins, 30 g / L glucose and appropriate mineral elements. The pH value of the culture medium was adjusted to 7.0 to maintain the optimal growth conditions of the microorganisms. After inoculation, the strain was cultured at 30°C and 180 rpm for 24-48 hours until the optical density (OD 600 ) reaches 0.8-1.0, at which time each strain is in an active growth phase and has efficient functional activity.

[0045] After the composite bacterial agent is expanded (added to a brown sugar culture medium at a mass ratio of 1:10 for expansion, the formula of the brown sugar culture medium is: 20g / L brown sugar, 2g / L soybean powder, 1g / L potassium dihydrogen phosphate, 1g / L magnesium sulfate and 1g / L sodium chloride, and the pH is adjusted to 5.5-7.5), an accelerator is added, the accelerator includes the following weight percentage components: 3% glucose, 2% γ-aminophosphoric acid, 2% sodium alginate and 2% glutamic acid, and the pH is adjusted to 6-7. The amount of the accelerator added is 5-11% of the total bacterial solution, and it is evenly sprayed on the composite bacterial agent. After the spraying is completed, the bacterial agent is left to stand for 2 hours to allow it to be fully absorbed and activated.

[0046] In actual application, the composite bacterial agent is evenly applied to the saline-alkali soil in the dry and hot valley by spraying to increase soil organic carbon accumulation and regulate the saline-alkali environment. The application amount is 1-3L / mu, and it is applied every 1-2 months to ensure that the soil organic carbon content is gradually increased and the degree of salinization is improved.

[0047] The following is further described in the form of specific embodiments.

[0048] Example 1

[0049] A microbial composite agent for promoting the accumulation of organic carbon in cultivated soil comprises the following components in parts by weight: 10 parts of carbon fixation functional bacteria and 20 parts of soil improvement bacteria.

[0050] Preparation method: Mix two bacterial liquids of Corynebacterium stagnantum and Microbacterium desintegratum in a volume ratio of 1:1 to obtain a carbon-fixing functional bacterial community; mix four bacterial liquids of Pseudomonas fluorescens, Bacillus megaceus, Bacillus mucilaginosus and Bacillus laterus in a volume ratio of 4:3:3:2 to obtain a soil improving bacterial community.

[0051] The carbon fixation functional bacteria and soil improvement bacteria are added into a sterile mixing container at a weight ratio of 1:2 under sterile conditions, and slowly stirred to ensure uniformity to obtain a microbial composite agent.

[0052] The obtained composite bacterial agent was placed in brown sugar medium at a volume ratio of 1:10 for expansion until the bacterial solution concentration reached the required level (OD 600 >1.0).

[0053] After expansion, add accelerator (3% glucose, 2% γ-aminophosphoric acid, 2% sodium alginate and 2% glutamic acid, adjust pH to 6-7). The amount of accelerator added is 5% of the total bacterial solution, and it is evenly sprayed on the composite bacterial agent. After spraying, let the bacterial agent stand for 2 hours to allow it to be fully absorbed and activated.

[0054] The composite bacterial agent is evenly applied to the soil surface by spraying. It is recommended to apply it in the early morning or evening to avoid the influence of direct sunlight on the activity of the bacteria. The application amount is controlled at 1-3L / mu and adjusted according to soil conditions and improvement needs.

[0055] Example 2

[0056] A microbial composite agent for promoting the accumulation of organic carbon in cultivated soil comprises the following components in parts by weight: 15 parts of carbon fixation functional bacteria and 20 parts of soil improvement bacteria.

[0057] Preparation method: Mix two bacterial liquids of Corynebacterium stagnantum and Microbacterium desintegratum in a volume ratio of 1:1 to obtain a carbon-fixing functional bacterial community; mix four bacterial liquids of Pseudomonas fluorescens, Bacillus megaceus, Bacillus mucilaginosus and Bacillus laterus in a volume ratio of 4:3:3:2 to obtain a soil improvement bacterial community.

[0058] The carbon fixation functional bacteria and soil improvement bacteria are added into a sterile mixing container at a weight ratio of 3:4 under sterile conditions, and stirred slowly to ensure uniformity to obtain a microbial composite agent.

[0059] The obtained composite bacterial agent was placed in brown sugar medium at a volume ratio of 1:10 for expansion until the bacterial solution concentration reached the required level (OD 600 >1.0).

[0060] After expansion, add accelerator (3% glucose, 2% γ-aminophosphoric acid, 2% sodium alginate and 2% glutamic acid, adjust pH to 6-7). The amount of accelerator added is 5% of the total bacterial solution, and it is evenly sprayed on the composite bacterial agent. After spraying, let the bacterial agent stand for 2 hours to allow it to be fully absorbed and activated.

[0061] The composite bacterial agent is evenly applied to the soil surface by spraying. It is recommended to apply it in the early morning or evening to avoid the influence of direct sunlight on the activity of the bacteria. The application amount is controlled at 1-3L / mu and adjusted according to soil conditions and improvement needs.

[0062] Example 3

[0063] A microbial composite agent for promoting the accumulation of organic carbon in cultivated soil comprises the following components in parts by weight: 20 parts of carbon fixation functional bacteria and 30 parts of soil improvement bacteria.

[0064] The two bacterial solutions of Corynebacterium stagnans and Microbacterium desmochromatum were mixed in a volume ratio of 1:1 to obtain a carbon-fixing functional bacterial community;

[0065] The four bacterial liquids of Pseudomonas fluorescens, Bacillus megaceus, Bacillus mucilaginosus and Bacillus laterus were mixed in a volume ratio of 4:3:3:2 to obtain a soil improving bacterial community.

[0066] The carbon fixation functional bacteria and soil improvement bacteria are added into a sterile mixing container at a weight ratio of 2:3 under sterile conditions, and slowly stirred to ensure uniformity to obtain a microbial composite agent.

[0067] The obtained composite bacterial agent was placed in brown sugar medium at a volume ratio of 1:10 for expansion until the bacterial solution concentration reached the required level (OD 600 >1.0).

[0068] After expansion, add accelerator (3% glucose, 2% γ-aminophosphoric acid, 2% sodium alginate and 2% glutamic acid, adjust pH to 6-7). The amount of accelerator added is 5% of the total bacterial solution, and it is evenly sprayed on the composite bacterial agent. After spraying, let the bacterial agent stand for 2 hours to allow it to be fully absorbed and activated.

[0069] The composite bacterial agent is evenly applied to the soil surface by spraying. It is recommended to apply it in the early morning or evening to avoid the influence of direct sunlight on the activity of the bacteria. The application amount is controlled at 1-3L / mu and adjusted according to soil conditions and improvement needs.

[0070] Comparative Example 1

[0071] The same as Example 1, the only difference is that the amount of the promoter added is 7% of the total bacterial liquid. The specific composition is as follows:

[0072] 10 parts of carbon fixation functional bacteria, 20 parts of soil improvement bacteria, and the amount of promoter added is 7% of the total bacterial solution.

[0073] Comparative Example 2:

[0074] The same as Example 1, the only difference is that the amount of the promoter added is 9% of the total bacterial liquid. The specific composition is as follows:

[0075] 10 parts of carbon fixation functional bacteria, 20 parts of soil improvement bacteria, and the amount of promoter added is 9% of the total bacterial solution.

[0076] Comparative Example 3:

[0077] The same as Example 1, the only difference is that the amount of the promoter added is 11% of the total bacterial liquid. The specific composition is as follows:

[0078] 10 parts of carbon fixation functional bacteria, 20 parts of soil improvement bacteria, and the amount of promoter added is 11% of the total bacterial solution.

[0079] Application Examples

[0080] The microbial composite agents provided in Examples 1-3 and Comparative Examples 1-3 were used as fertilizers, and were evenly applied to the saline-alkali soil in the dry hot valley by spraying at an application rate of 1L / mu, and corn was planted respectively as the experimental group. The saline-alkali land without any treatment was directly planted with corn as the control group. The application was applied once every month, and in the third month, the soil surface samples were taken for analysis and detection.

[0081] The present invention systematically tests the effect of the microbial composite agent, and the specific testing method is as follows:

[0082] 1. Determination of soil organic carbon content

[0083] To evaluate the effect of microbial composite agents on soil organic carbon accumulation, the Walkley-Black method was used for determination. The specific steps are as follows: Take 5g of soil samples before and after application, and add 20mL of potassium dichromate solution respectively. Stir the mixture evenly, let it stand for 30 minutes, and then add sulfuric acid solution for reaction. Use standard titration method to determine the amount of unreacted potassium dichromate and calculate the soil organic carbon content.

[0084] 2. Salinity analysis

[0085] In order to determine the changes in soil salinity after the application of the microbial compound agent, the conductivity method was used for analysis. The specific steps are: sample the soil and mix it with deionized water in a ratio of 1:1. After standing for 1 hour, use a conductivity meter to measure the conductivity (EC) of the soil solution to evaluate the salinity of the soil. Conductivity is an important indicator to measure the degree of soil salinization. The higher the conductivity, the more serious the degree of soil salinization.

[0086] Determine the soil pH value: Take an appropriate amount of soil sample, about 10g, add an equal amount of deionized water (the ratio is 1:1 in this embodiment), stir evenly and let it stand for 30 minutes to 1 hour to allow the soil and water to react fully. Then use a pH meter to measure the pH value of the mixed solution and record the result.

[0087] 3. Analysis of rhizosphere microbial activity

[0088] The number and types of rhizosphere microorganisms were evaluated by sampling rhizosphere soil and culturing it with selective medium. The specific steps are as follows: sampling rhizosphere soil, diluting it and inoculating it on selective medium. Cultivating it under suitable conditions for 48 hours, counting the number of colonies of each microorganism, and analyzing the diversity of rhizosphere microorganisms and their correlation with plant growth.

[0089] 4. Results

[0090] The present invention systematically tests the effect of the microbial composite agent, focusing on evaluating its effect in increasing soil organic carbon content, improving salinity, promoting plant growth and rhizosphere microbial activity. The experimental group includes Examples 1, 2, 3 and Comparative Examples 1, 2, 3, and the control group is saline-alkali soil without the application of microbial agents.

[0091] 4.1 Changes in soil organic carbon content

[0092] Example 1: Three months after application, the soil organic carbon content increased from 1.2 g / kg before application to 1.6 g / kg.

[0093] Example 2: Three months after application, the soil organic carbon content increased from 1.0 g / kg to 1.1 g / kg.

[0094] Example 3: Three months after application, the soil organic carbon content increased from 1.1 g / kg to 1.3 g / kg.

[0095] Comparative Example 1: Three months after application, the soil organic carbon content increased from 1.2g / kg to 1.4g / kg.

[0096] Comparative Example 2: Three months after application, the soil organic carbon content increased from 1.2g / kg to 1.3g / kg.

[0097] Comparative Example 3: Three months after application, the soil organic carbon content increased from 1.1g / kg to 1.3g / kg

[0098] Control group: The soil organic carbon content remained at 1.2g / kg before and after application, with no significant changes.

[0099] 4.2 Changes in soil EC

[0100] Example 1: 3 months after application, the conductivity dropped from 4.5 mS / cm to 2.5 mS / cm.

[0101] Example 2: 3 months after application, the conductivity dropped from 4.4 mS / cm to 3.2 mS / cm.

[0102] Example 3: 3 months after application, the conductivity dropped from 4.4 mS / cm to 3.5 mS / cm.

[0103] Comparative Example 1: 3 months after application, the conductivity dropped from 4.5 mS / cm to 4.0 mS / cm.

[0104] Comparative Example 2: 3 months after application, the conductivity dropped from 4.5 mS / cm to 4.2 mS / cm.

[0105] Comparative Example 3: 3 months after application, the conductivity dropped from 4.5 mS / cm to 4.3 mS / cm.

[0106] Control group: The conductivity remained at 4.5 mS / cm, with no significant improvement.

[0107] 4.3 Changes in soil pH

[0108] Example 1: Three months after application, the soil pH value decreased from 8.2 to 7.4.

[0109] Example 2: Three months after application, the soil pH value decreased from 8.1 to 7.6.

[0110] Example 3: Three months after application, the soil pH value decreased from 8.0 to 7.5.

[0111] Comparative Example 1: 3 months after application, the soil pH value decreased from 8.2 to 8.1.

[0112] Comparative Example 2: Three months after application, the soil pH value decreased from 8.2 to 7.9.

[0113] Comparative Example 3: Three months after application, the soil pH value decreased from 8.3 to 8.1.

[0114] Control group: The soil pH value remained at 8.3, with no significant changes.

[0115] 4.4 Changes in rhizosphere microbial activity

[0116] Example 1: The total number of rhizosphere microorganisms increased from 2.5×10 5 cfu / g increased to 1.8×10 6 cfu / g, mainly including carbon fixation functional bacteria and soil improving bacteria.

[0117] Example 2: The total number of rhizosphere microorganisms increased from 2.8×105 cfu / g increased to 1.5×10 6 cfu / g, showing good diversity.

[0118] Example 3: The total number of rhizosphere microorganisms increased from 2.7×10 5 cfu / g increased to 1.6×10 6 cfu / g, with rich microbial species.

[0119] Comparative Example 1: The total number of rhizosphere microorganisms increased from 2.5×10 5 cfu / g increased to 5.0×10 5 cfu / g, showing less diversity.

[0120] Comparative Example 2: The total number of rhizosphere microorganisms increased from 2.6×10 5 cfu / g increased to 4.5×10 5 cfu / g, the microbial species are relatively single.

[0121] Comparative Example 3: The total number of rhizosphere microorganisms increased from 2.8×10 5 cfu / g increased to 4.0×10 5 cfu / g, with little change.

[0122] Control group: The total number of rhizosphere microorganisms fluctuated and finally reached 3.0×10 5 cfu / g, showing the least diversity.

[0123] Table 1 Soil results at different application levels

[0124] index Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Organic carbon content (g / kg) 1.6 1.1 1.3 1.4 1.3 1.3 Conductivity (mS / cm) 2.5 3.2 3.5 4.0 4.2 4.3 pH 7.4 7.6 7.5 8.1 7.9 8.1 Rhizosphere microbial activity (cfu / g) <![CDATA[1.8×10 6 ]]> <![CDATA[1.5×10 6 ]]> <![CDATA[1.6×10 6 ]]> <![CDATA[5.0×10 5 ]]> <![CDATA[4.5×10 5 ]]> <![CDATA[4.0×10 5 ]]>

[0125] Note: Different letters in each line indicate statistically significant differences.

[0126] Table 2 Effects of applying microbial agents on soil

[0127] index Control group Example 1 Organic carbon content (g / kg) 1.2 1.6 Conductivity (mS / cm) 4.5 2.5 pH 8.3 7.4 Rhizosphere microbial activity (cfu / g) <![CDATA[3.0×10 5 ]]> <![CDATA[1.8×10 6 ]]>

[0128] Note: Different letters in each line indicate statistically significant differences.

[0129] According to Table 1, when a suitable proportion of the microbial composite agent is applied, the soil organic carbon content increases, the conductivity decreases, the pH decreases, and the microorganisms gradually become richer after 3 months. Among them, Example 1 is the best embodiment. Experiments have shown that each bacterial community and promoter in the agent play an important role, and they need to be mixed according to the fixed ratio of Example 1 to achieve the best effect.

[0130] According to Table 2, the microbial composite agent of the present invention for dry and hot valley areas can not only improve local soil and alleviate soil salinization problems, but also effectively increase soil organic carbon content and optimize soil fertility through the collaboration between specific microbial flora. Based on the above test results, the microbial composite agent showed significant effects in increasing soil organic carbon content, improving salinity and increasing rhizosphere microbial activity. In addition, the application of microbial composite agents in dry and hot valley areas has obvious advantages, proving its importance in promoting sustainable agricultural development.

[0131] The microbial composite agent of the present invention was evaluated for its promoting effect on soil organic carbon accumulation through a systematic testing method, and the results showed that the agent can effectively increase the soil organic carbon content and improve the characteristics of salinized soil. Comparative analysis of the examples and comparative examples shows that optimized culture conditions and appropriate promoter addition have a significant positive effect on improving soil quality and plant growth, providing effective technical support and reference for agricultural practices in dry and hot valley areas.

[0132] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A microbial composite agent for promoting the accumulation of organic carbon in cultivated soil, characterized in that: The microbial composite agent comprises 10-20 parts by weight of carbon fixation functional bacteria and 20-30 parts by weight of soil improvement bacteria; The carbon fixation functional bacteria include Corynebacterium stationis and Hyphomicrobium denitrificans; the soil improvement bacteria include Pseudomonas fluorescens, Bacillus megaterium, Bacillus mucilaginosa and Bacillus lateralis.

2. The microbial composite agent according to claim 1, characterized in that The stagnant Corynebacterium is stagnant Corynebacterium CGMCC 1.844, and the apoptotic microbacterium is apoptotic microbacterium CGMCC 1.15943; The stagnant Corynebacterium and the desmochromatium are mixed in the form of bacterial liquid, and the volume ratio of the stagnant Corynebacterium bacterial liquid to the desmochromatium bacterial liquid is 1:1; The OD of the stagnant Corynebacterium solution and the desingle-hyphalomycete solution 600 Both are 0.8-1.

0.

3. The microbial composite agent according to claim 1, characterized in that: The Pseudomonas fluorescens is Pseudomonas fluorescens CICC 20066, and the Bacillus megaterium is Bacillus megaterium CICC 10044; The Pseudomonas fluorescens, Bacillus megaceus, Bacillus mucilaginosus and Bacillus laterus are mixed in the form of bacterial liquid, and the volume ratio of the Pseudomonas fluorescens bacterial liquid, the Bacillus megaceus bacterial liquid, the Bacillus mucilaginosus bacterial liquid and the Bacillus laterus bacterial liquid is 4:3:3:2; The OD values ​​of the Pseudomonas fluorescens bacterial solution, the Bacillus megaceus bacterial solution, the Bacillus mucilaginosus bacterial solution and the Bacillus laterus bacterial solution were 600 Both are 0.8-1.

0.

4. A method for preparing the microbial composite agent according to any one of claims 1 to 3, characterized in that: The following steps are involved: The stagnant Corynebacterium and the desmochromatin Microbacterium are mixed in proportion to obtain a carbon-fixing functional bacterial community; Pseudomonas fluorescens, Bacillus megaceus, Bacillus mucilaginosus and Bacillus laterus are mixed in proportion to obtain soil improving bacteria flora; The carbon fixation functional bacteria and the soil improvement bacteria are mixed in proportion to obtain a microbial composite agent.

5. The preparation method according to claim 4, characterized in that: The method also includes the steps of expanding the culture of the microbial composite agent and adding a promoter.

6. The preparation method according to claim 5, characterized in that: Using brown sugar culture medium to carry out the expansion culture; The brown sugar culture medium comprises the following components: 20 g / L brown sugar, 2 g / L soybean powder, 1 g / L potassium dihydrogen phosphate, 1 g / L magnesium sulfate and 1 g / L sodium chloride, and the pH value is 5.5-7.

5.

7. The preparation method according to claim 5, characterized in that: The accelerator is composed of the following ingredients in weight percentage: 3% glucose, 2% γ-aminophosphoric acid, 2% sodium alginate and 2% glutamic acid, with a pH of 6-7; The amount of the accelerator added is 5-11 wt%.

8. Use of the microbial composite agent according to any one of claims 1 to 3 in improving soil salinization in dry-hot valleys and promoting organic carbon accumulation.

9. A method for improving soil salinization and promoting organic carbon accumulation in dry hot valleys, characterized in that: The method comprises the step of applying the microbial composite agent according to any one of claims 1 to 3 to the soil of a dry hot valley.

10. The method according to claim 9, characterized in that The application amount of the microbial composite agent is 1-3L / mu.